Novel Dried Blood Spot Mass Spectrometry Functional Assays for Lysosomal Acid Lipase and N-acetylgalactosamine-sulfate Sulfatases for Use in Newborn Screening

用于新生儿筛查的溶酶体酸性脂肪酶和 N-乙酰半乳糖胺硫酸酯硫酸酯酶的新型干血斑质谱功能分析

• 批准号: 9238498
• 负责人: Sophia Masi
• 金额: $ 4.9万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-16 至 2019-09-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9238498
• 关键词: Acetylgalactosamine; Acid Lipase; Affect; Atherosclerosis; Biological Assay; Blood; Cessation of life; Child; Cholesterol; Cholesterol Ester Storage Disease; Cholesterol Esters; Cleaved cell; Clinical; Connective Tissue; Coupling; Daughter; Defect; Development; Diagnosis; Diagnostic tests; Disease; Eligibility Determination; Enzymes; Esters; GALNS gene; Galactosamine; Glycosaminoglycans; Health; Human; Hydrolysis; Incidence; Infant; Intervention; Ions; Leukocytes; Life; Lysosomal Storage Diseases; Mass Spectrum Analysis; Metabolism; Mucopolysaccharidoses; Mucopolysaccharidosis IV A; Mucopolysaccharidosis VI; Neonatal Screening; Outcome; Pathway interactions; Patients; Phase III Clinical Trials; Protocols documentation; Rare Diseases; Savings; Scanning; Serum; Source; Spottings; Sulfatases; Supportive care; Transportation; Triglycerides; Unspecified or Sulfate Ion Sulfates; Wolman Disease; cost; design; diagnostic assay; emerging adult; enzyme activity; enzyme replacement therapy; improved; inhibitor/antagonist; liver function; novel; public health relevance; screening; skeletal tissue; tandem mass spectrometry

 DESCRIPTION (provided by applicant): Defects in the human cholesterol transportation pathway can create two ultimately fatal recessive diseases (Wolman's disease and Cholesterol Ester Storage disease or CESD). The responsible enzyme, lysosomal acid lipase or LAL, is unable carry out its cholesterol ester hydrolysis function, resulting in a severe decline in liver function for Wolman's disease patients and a rapid increase in both cholesterol and triglyceride levels in blood serum with increased incidence of atherosclerotic disease in CESD patients' vessels by early adulthood. Yet, no recommended or universal diagnostic assay exists for either of these two diseases, resulting in many missed cases. By using a specific LAL substrate or an existing irreversible inhibitor of LAL, we will be able to specifically assay LAL enzymatic activit in dried blood spots. Likewise, the development of a more sensitive DBS assay for the more rare mucopolysaccharidoses (MPS) types IVA and VI will greatly benefit screening and diagnosing deficiencies due to the low baseline activity of these enzymes. The use of dried blood spots (DBS) is a low cost, relatively long-lived source of the enzymes found in leukocytes. Mass spectrometry will serve to quantify the amount of cleaved substrate from daughter ion fragmentation (or MS/MS scans), providing a high sensitivity for even small changes in enzyme function, which is critical for minimizing false positives in clinical settings. The development of an MS/MS dried blood spot assay for LAL deficiencies as well as improved MPS IVA and VI MS/MS DBS assays will provide newborn screening centers a means to efficiently identify potential cases that require immediate intervention and potentially life-long therapy that will protect the lives of these affected children.

 描述（由适用提供）：人类胆固醇运输途径中的缺陷可以造成两种最终致命的隐性疾病（沃尔曼氏病和胆固醇酯储存疾病或CESD）。负责的酶，溶酶体酸性脂肪酶或LAL无法执行其胆固醇酯的水解功能，导致沃尔曼病患者的肝功能严重下降，并且早期的Adther疾病患者的发生率增加了沃尔曼病患者的血清中胆固醇和甘油三甘油的水平迅速升高。但是，这两种疾病尚无建议或普遍的诊断测定，导致许多遗漏。通过使用特定的LAL底物或LAL的现有不可逆抑制剂，我们将能够在干血点中特别主张LAL酶活性。同样，由于这些酶的基线活性较低，对更罕见的粘多糖糖（MPS）类型的较稀有粘多糖（MPS）类型的DBS评估的发展将很大。干燥的血液点（DBS）是白细胞中发现的酶的相对寿命相对较长的来源。质谱法将用于量化子离子碎片（或MS/MS扫描）的切割底物的量，从而为酶功能的少量变化提供了高灵敏度，这对于最大程度地减少了临床环境中的假阳性至关重要。发展的发展 MS/MS干燥的血点分析，可用于LAL缺陷以及改善的MPS IVA和VI MS/MS DBS分析，将为新生儿筛查中心提供有效识别需要立即干预的潜在病例的手段，这些病例需要立即进行干预以及可能终身疗法，以保护这些受影响儿童的生活。